With the advancement of wireless communication technologies in recent years, people's demand for communication and data transmission via wireless devices has increased. In order to extend the signal coverage or ease the network congestion, wireless network operators are actively setting up small cells in places where there is a dense population or the signal strength is poor.
In the current 3rd Generation Partnership Project (3GPP) network protocol, a user equipment must be located within the signal coverage of a macro base station in order to know the presence of a small cell that is in an off-state via the macro base station. Furthermore, switching the small cell from the off-state to an on-state can only be accomplished by the macro base station via a backhaul network.
Accordingly, user equipments (especially those just started up or those having lost an effective connection) located out of the signal coverage of the macro base station can never know the presence of a small cell that is in the off-state. In addition, because switching of the small cell from the off-state to the on-state the small cell is triggered by the macro base station via the backhaul network in the conventional mechanism, there inevitably exists a delay.
In view of this problem, an urgent need exists in the art to provide an operation mechanism for a small cell which reduces the delay when the small cell is triggered to be switched from the off-state to the on-state and which allows a user equipment located out of the signal coverage of a macro base station to know the presence of the small cell.